Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755059Ab1FOVxl (ORCPT ); Wed, 15 Jun 2011 17:53:41 -0400 Received: from mail-yw0-f46.google.com ([209.85.213.46]:61285 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752166Ab1FOVxj (ORCPT ); Wed, 15 Jun 2011 17:53:39 -0400 Message-ID: <4DF929E0.1030806@codemonkey.ws> Date: Wed, 15 Jun 2011 16:53:36 -0500 From: Anthony Liguori User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110424 Lightning/1.0b2 Thunderbird/3.1.10 MIME-Version: 1.0 To: Prasad Joshi CC: Pekka Enberg , Avi Kivity , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Andrew Morton , Linus Torvalds , Ingo Molnar , Sasha Levin , Cyrill Gorcunov , Asias He , Jens Axboe Subject: Re: [ANNOUNCE] Native Linux KVM tool v2 References: <1308153214.7566.6.camel@jaguar> <4DF8DE26.1070301@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1432 Lines: 37 On 06/15/2011 03:13 PM, Prasad Joshi wrote: > On Wed, Jun 15, 2011 at 6:10 PM, Pekka Enberg wrote: >> On Wed, Jun 15, 2011 at 7:30 PM, Avi Kivity wrote: >>> On 06/15/2011 06:53 PM, Pekka Enberg wrote: >>>> >>>> - Fast QCOW2 image read-write support beating Qemu in fio benchmarks. See >>>> the >>>> following URL for test result details: https://gist.github.com/1026888 >>> >>> This is surprising. How is qemu invoked? >> >> Prasad will have the details. Please note that the above are with Qemu >> defaults which doesn't use virtio. The results with virtio are little >> better but still in favor of tools/kvm. >> > > The qcow2 image used for testing was copied on to /dev/shm to avoid > the disk delays in performance measurement. Our experience has been that this is actually not a great way to simulate fast storage. Spindle based storage has very different characteristics than memory as there is a significant cost for seeking. -hdb uses IDE too. That's pretty unfair since IDE is limited to a single request at a time whereas virtio can support multiple requests (and native kvm tools is using virtio). Regards, Anthony Liguori -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/